I have a couple instrument assemblies and I just discovered there is a difference with the Speedos???If you look at the picture you will see a little electronic box added to one of the speedos and it is OEM. What the heck is it for. I plan to list both assemblies in the classified but would like to know what this is before I list.ThanksAndrew

The rusty box? I think it's a speed switch probably for emissions. Notice that one speedo stops or starts at 10 MPH and the other at Zero? My B-210 had something like this. When the needle touches the 10MPH it opens a switch I think.

On deceleration my B-210 had a very slight fast idle. As you slow in first gear the speedometer touched 10MPH the engine would lurch down to it's set idle speed. Perhaps a rudimentary BCDD to lower emissions.

"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs